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SHA-512 with salt not matching between Java and PHP

My application uses salted hash in Java. First a random salt is generated. Then this salt is prefixed to the SHA-512 of the input password and the combined string is SHA-512 again.It is implemented as follows:-
String password = testpwd.getText().toString();
SecureRandom rand = new SecureRandom();
byte[] randbytes = new byte[16];
rand.nextBytes(randbytes);
String encodedSalt = Base64.encodeToString(randbytes, Base64.DEFAULT);
MessageDigest digest = MessageDigest.getInstance("SHA-512");
digest.reset();
digest.update(password.getBytes("utf-8"));
byte[] pwdhash = digest.digest();
String encodedPwd = Base64.encodeToString(pwdhash, Base64.DEFAULT);
String saltedPassword = encodedSalt+encodedPwd ;
digest.reset();
digest.update(saltedPassword.getBytes("utf-8"));
byte[] pwdhash1 = digest.digest();
String encodedPwdSalt = Base64.encodeToString(pwdhash1, Base64.DEFAULT);
Then the strings encodedSalt and encodedPwdSalt are sent to web server for authentication. The PHP encryption is as follows:
$postpassword = $_POST['password'];
$postsalt = $_POST['salt'];
$salt = base64_decode($postsalt);
$password = base64_decode('postpassword');
The SHA-512 hashs of the password "Ditglt#785" is stored in the database. It is retrieved and processed as follows:-
$getsaltpwd = $salt.$dbpassword ;
$dbsaltpwd = hash('sha512', $getsaltpwd);
if($dbpassword == $postpassword) {}
The condition always fails and so does the authentication. What should I do ?

The PHP version hashes raw bytes while the Java version hashes base64-encoded strings.
Here's a Java version that matches what your PHP code does:
digest.reset();
digest.update(randbytes);
digest.update(pwdhash);
byte[] pwdhash1 = digest.digest();
String encodedPwdSalt = Base64.encodeToString(pwdhash1, Base64.DEFAULT);
Having said that, it would be more secure to store the salt and the salted password in the database, and to use at least some key derivation function (iterate the hash function many times) in order to counteract any potential brute-forcing of the stored hashes.

Since your Java code correctly follows what you describe in your specification, the problem lies on the PHP side.
With your Java code as-is, it generates the following values when encoding the string "password" with a random salt:
encodedSalt: ww0g+f77ygKD7Iww1GTYtg==
encodedPwd: sQnzu7wkTrgkQZF+0G1hi5AI3Qmzvv0bXgc5THBqi7mAsdd4Xll27ASbRt9fEyavWi6m0QP9B8lThf+rDKy8hg==
encodedPwdSalt: YAGG7GcpUxIZzBnHuaezPf5BWFhFalBPgvue/0wFoRLu+JsKslG8wPCv6dPubIBk1aFIJ8spK8S17347aDBAYA==
In PHP, what you would need to do is the following:
$postpassword = 'YAGG7GcpUxIZzBnHuaezPf5BWFhFalBPgvue/0wFoRLu+JsKslG8wPCv6dPubIBk1aFIJ8spK8S17347aDBAYA==';
$postsalt = 'ww0g+f77ygKD7Iww1GTYtg==';
$dbpassword = 'sQnzu7wkTrgkQZF+0G1hi5AI3Qmzvv0bXgc5THBqi7mAsdd4Xll27ASbRt9fEyavWi6m0QP9B8lThf+rDKy8hg==';
if($postpassword == base64_encode(hash('sha512', $postsalt.$dbpassword, true))) {
echo 'OK';
}

Check if the padding matches. I experienced the same problem with encryption where the padding in PHP was different from the padding in JAVA. Luckily I was able to set the padding in JAVA to the one that PHP uses. But I had to look at PHP source code to figure out how. As far as I remember it was not possible to change the padding in PHP back then.
Here is the question I posted back then: decrypting php encrypted data on android
[...] you need to set Base64.decode with the parameter Base64.NO_WRAPas PHP will just put out the base64 delimited by \0.

JAVA DES Encryption Output Encoding

I have DES Encryption Algorithm implementation in JAVA (javax.crypto.Cipher), it is successfully encoding and decoding (most) strings... the problem is that, sometimes, it message specific blocks (since DES uses 8-character blocks in block mode).
In my case, almost always the 3rd block is messed up and rest shows fine.
for example:
key: thisiskey
message to encrypt: Google is an American multinational technology company specializing in Internet-related services
encrypted message (in UTF-8):
mñqè•ÀPŒ�øf"
ߦ\±õ¤ù'È9¢ëyT ÍQEÁ|;ëâÉ÷JWú
Now, when i go and decrypt this, i get this:
Decrypted message:
Google i,í\O¯‹Ýbº-¸�¬ltinational technology company specializHôJ—=ÊÍnternet-related services
As far as i understand the issue, it is due to the fact that UTF-8 CANNOT show all characters and thus, while showing as well as copying for decryption, this problem occurs.
Can anyone suggest me a solution?
Preferably, either a character-set that can handle this, or, a way to convert Binary directly to HEX (that can be output to user) and then Vice Versa (decrypted, after copying/pasting) in JAVA.
EDIT
This is 'approximate' code, not exact (for example encrypted message is not properly paste-able and these are parts of the function, but it should give the idea). Even in base64 encoding , i am unable to get this decrypted properly.
Encrypt Function code:
boolean base64 = true;
key = "thisiskey";
plainText = "Google is an American multinational technology company specializing in Internet-related services";
SecretKeyFactory MyKeyFactory = SecretKeyFactory.getInstance("DES");
byte[] keyBytes = key.getBytes();
DESKeySpec generatedKeySpec = new DESKeySpec(keyBytes);
SecretKey generatedSecretKey = MyKeyFactory.generateSecret(generatedKeySpec);
Cipher generatedCipher = Cipher.getInstance("DES");
generatedCipher.init(Cipher.ENCRYPT_MODE, generatedSecretKey);
byte[] messsageStringBytes = plainText.getBytes();
byte[] encryptedMessage = generatedCipher.doFinal(messsageStringBytes);
String encryptedMessageString = new String(encryptedMessage);
if (base64) {
encryptedMessageString = Base64.getEncoder().encodeToString(encryptedMessageString.getBytes("utf-8"));
}
return encryptedMessageString;
Decrypt Function code:
boolean dbase64 = true;
dkey = "thisiskey";
messageToDecrypt = "mñqè•ÀPŒ�øf\"ߦ\±õ¤ù'È9¢ëyT ÍQEÁ|;ëâÉ÷JWú"; // Message from above code
SecretKeyFactory MyKeyFactory = SecretKeyFactory.getInstance("DES");
byte[] dkeyBytes = dkey.getBytes();
DESKeySpec generatedKeySpec = new DESKeySpec(dkeyBytes);
SecretKey generatedSecretKey = MyKeyFactory.generateSecret(generatedKeySpec);
Cipher generatedCipher = Cipher.getInstance("DES");
generatedCipher.init(Cipher.DECRYPT_MODE, generatedSecretKey);
if (dbase64) {
byte[] decodedBytes = Base64.getDecoder().decode(dencryptedText);
dencryptedText = new String(decodedBytes, "utf-8");
}
byte[] messsageStringBytes = dencryptedText.getBytes();
byte[] encryptedMessage = generatedCipher.doFinal(messsageStringBytes);
String decryptedMessageString = new String(encryptedMessage);
return decryptedMessageString;

"Encrypted message in UTF-8" makes no sense. The ciphertext is binary and not UTF-8. You need to put it into a byte[], not a String.
If you need a String, use Base64 or Hex encoding.
Even in base64 encoding , i am unable to get this decrypted properly.
String encryptedMessageString = new String(encryptedMessage);
if (base64) {
encryptedMessageString = Base64.getEncoder().encodeToString(encryptedMessageString.getBytes("utf-8"));
}
That does not work. You are encoding to Base64 after the data is already broken (by calling new String). Do not put it in a String at all. Go directly from encryptedMessage (the byte[]) to Base64.

encrypt and decrypt string

I have a question regarding encrypting and decrypting a string
I have to send a encrypted string over the network.(an android app is the client) this is what i did so far
byte[] input = getByteArray(filePath);//get the message stored in a file as a byte array
by going through some tutorial i managed to get the String message to a byte array and
encrypted it using javax.crypto
Cipher cipher = Cipher.getInstance("DES/CBC/PKCS5Padding");
cipher.init(Cipher.ENCRYPT_MODE, key, ivSpec);
encrypted msg is retrived as a byte array
byte[] encrypted
i even managed to decrypt it using the reverse method and get the message again
but my problem comes when i try to convert this encrypted byte array to strings (to pass it over the network)
and then reconvert it to a byte array
i tryed this
String encryptedStrn = new String(encrypted); // convert to string
when i convert it to the byte array by
byte[] enc = encryptedStrn.getBytes();
and use this enc array to decrypt but the output does not come correctly.
Have i missed some basic stuff regarding converting. Please help me.
thanks in advance

As CodeInChaos wrote in a comment, you shouldn't use the String(byte[]) constructor to create a string from opaque binary data. The string constructors are intended for text data which has been encoded using an encoding like ASCII, UTF-8 etc. Opaque binary data such as the result of encryption, or an image file, is not encoded text data in the same way, so you end up losing information.
You should use base64 instead, which encodes any binary data into ASCII. There are various 3rd party libraries for this, including a good public domain one. Alternatively, on Android you can just use the Base64 class.
Additionally, even when you are encoding or decoding real text, you shouldn't use String.getBytes() and the String(byte[]) constructor anyway - they use the platform default encoding, which is almost always the wrong choice. Instead, you should use the overloads which explicitly take a CharSet or the name of a character encoding. UTF-8 is typically a good encoding to use if you're able to control both ends - if you're only controlling one end, you need to know which encoding the other end is expecting.

You should base64-encode the cipher text. Don't just convert it to a String. String is not a container for binary data.

public string EncryptUser(string userID)
{
using (var cryptoProvider = new DESCryptoServiceProvider())
using (var memoryStream = new MemoryStream())
using (var cryptoStream = new CryptoStream(memoryStream, cryptoProvider.CreateEncryptor(DESKey, DESInitializationVector), CryptoStreamMode.Write))
using (var writer = new StreamWriter(cryptoStream))
{
writer.Write(userID);
writer.Flush();
cryptoStream.FlushFinalBlock();
writer.Flush();
return Convert.ToBase64String(memoryStream.GetBuffer(), 0, (int)memoryStream.Length);
}
}
public string DecryptUserID(string userID)
{
using (var cryptoProvider = new DESCryptoServiceProvider())
using (var memoryStream = new MemoryStream(Convert.FromBase64String(userID)))
using (var cryptoStream = new CryptoStream(memoryStream, cryptoProvider.CreateDecryptor(DESKey, DESInitializationVector), CryptoStreamMode.Read))
using (var reader = new StreamReader(cryptoStream))
{
return reader.ReadToEnd();
}
}

Passing gzencoded data to mcrypt_encrypt, can't unzip after decryption

To keep this short, are there known issues when passing results of gzencode (or other non-text data) to mcrypt_encrypt functions?
Details:
Basically I have an issue where encryption/decryption is working for plain text but I get errors unzipping if I pass compressed data to the encryption function, then decrypt and unzip.
So in PHP, I'm passing results of gzencode() to the encrypt function. Then I base64 encode for showing results on a web service web page. Then in a Java app I'm decoding base64, decrypting, and unzipping using GZIPInputStream. I get errors in the last step.
But everything works fine if I skip the compression step (just pass plain text to the encrypt function). Everything also works fine if I skip encryption and just do compression. So those functions seem to work fine on both PHP and Java sides if I don't combine them.
public static function encrypt($str,$key,$iv) {
$str=Crypto2::pkcs5Pad($str,mcrypt_get_block_size(MCRYPT_RIJNDAEL_128, MCRYPT_MODE_CBC));
$encrypted=mcrypt_encrypt(MCRYPT_RIJNDAEL_128,$key,$str,MCRYPT_MODE_CBC,$iv);
return $encrypted;
}
public static function pkcs5Pad ($text, $blocksize) {
$pad = $blocksize - (strlen($text) % $blocksize);
$padded=$text . str_repeat(chr($pad), $pad);
return $padded;
}
Java functions:
public static byte[] decrypt(byte[] inputbuffer) throws Exception {
Key key = new SecretKeySpec(keybyte, "AES");
IvParameterSpec ivSpec = new IvParameterSpec(iv);
Cipher c = Cipher.getInstance("AES/CBC/PKCS5Padding");
c.init(Cipher.DECRYPT_MODE, key, ivSpec);
c.getBlockSize();
System.out.println("Block size="+c.getBlockSize());
int outlen = c.getOutputSize(inputbuffer.length);
System.out.println("Output length will be:"+outlen);
byte[] result=c.doFinal(inputbuffer);
return result;
}
public static byte[] decodeBase64(String data) throws IOException{
BASE64Decoder decoder = new BASE64Decoder();
byte[] decodedBytes = decoder.decodeBuffer(data);
return decodedBytes;
}
public static void unzipPrint(byte[] data) throws Exception{
InputStream is=new GZIPInputStream(new ByteArrayInputStream(data));
int ch2;
while((ch2=is.read())!=-1) {
System.out.print((char)ch2);
}
}
So if I do this in PHP:
base64_encode(encrypt(gzencode($plain_text)));
and this in Java
unzipPrint(decrypt(decodeBase64(data)));
I get the dreaded: "java.util.zip.ZipException: oversubscribed dynamic bit lengths tree" during the unzip phase.
Again, if I skip the compression/decompression steps at both ends everything is fine. And if I skip encryption at both ends then compression/decompression works fine.
EDIT: Ok weird, but after checking byte by byte the resulting byte array of the compressed data (after decoding base64 and decryption), I found a SINGLE byte that was off (compared to the original PHP byte array) by a value of 1. It was byte number 14 (index 13 in Java) and it had a value of 110 instead of 111. I have absolutely no idea how this could be the case.
So if I change that single byte to from 110 to 111, then I can successfuly use GZIPOutputStream to uncompress the data.
So I know what is wrong but not why.
EDIT 2: This is SOLVED ->Thanks to comment by Owlstead I double checked the IV values and found that there was minor descrepancy between the php and java code. How this can lead to only one byte of difference in the resulting decrypted data I have no idea.
That was one wasted day over a single 0x13 instead of 0x12 in my IV.

You should check the IV, as it may change only the first block of cipher text, which holds the ZIP header.
(to close the question, glad you got it solved, any day that you solve an issue is not one wasted in my opinion :) )

Can you get this same Java SHA-1 in PHP please?

I find myself in a need to change website platforms from Java to PHP but I'd like to keep all my user's passwords...
I had this code do the password hashing prior to writting the hashed value as the password to the website:
MessageDigest md = null;
md = MessageDigest.getInstance("SHA");
md.update(plaintext.getBytes("UTF-8"));
byte raw[] = md.digest();
hash = new Base64().encodeToString(raw).replaceAll("\n", "").replaceAll("\r", "");
I think the Java code did SHA-1 hashing of the password but just prior to that it was byte encoded to UTF-8 and afterwards it was Base64 encoded.
I'd like to have a PHP code do the same, i.e. return the same value of a hash for the same password as in Java, only it seems that the PHP code doing SHA-1 hashing I have won't return the same SHA(-1, not Base64 encoded, I think?) value when compared to a Java Base64 decoded value of the hash...could it have something to do with the fact that my passwords in PHP are not UTF-8 byte encoded first (and how can I do that in PHP) please?
p.s.
Another strange thing...my passwords in Java are all 28characters long (usually something like this rnwn4zTNgH30l4pP8V05lRVGmF4=)...but the Base64().decode(hash) value of those password hashes is 10 characters long (an example [B#14e1f2b).
I thought Base64 did an additional 1 character to each 3 charters (28 or 27, excluding the padding = charter, is much more that a third larger than those 10 charcters) so am I doing the decoding call wrong somehow maybe???
And on top of all that the SHA-1 password hashed values in PHP are 40 characters long (in a UTF-8 mysql database) like so dd94709528bb1c83d08f3088d4043f4742891f4f?

[B#14e1f2b is definitely not a hash. It's a result of implicit conversion from byte[] to String.
It looks like you do something like this:
String decodedHash = Base64().decode(hash); // Produces [B#14e1f2b
However, the correct representation of the hash is a byte array:
byte[] decodedHash = Base64().decode(hash);

What I normally do with Java to compute a SHA-1 hash that is exactly identical to the PHP sha1() function is the following. The key is that toHexString is used to show the raw bytes in a printable way. If you use the PHP function and want to obtain the same result of your convoluted process, you need to use the parameter $raw_output to true in PHP to get the raw bytes and apply Base64. Full source code.
/**
* Compute a SHA-1 hash of a String argument
*
* #param arg the UTF-8 String to encode
* #return the sha1 hash as a string.
*/
public static String computeSha1OfString(String arg) {
try {
return computeSha1OfByteArray(arg.getBytes(("UTF-8")));
} catch (UnsupportedEncodingException ex) {
throw new UnsupportedOperationException(ex);
}
}
private static String computeSha1OfByteArray(byte[] arg) {
try {
MessageDigest md = MessageDigest.getInstance("SHA-1");
md.update(arg);
byte[] res = md.digest();
return toHexString(res);
} catch (NoSuchAlgorithmException ex) {
throw new UnsupportedOperationException(ex);
}
}
private static String toHexString(byte[] v) {
StringBuilder sb = new StringBuilder(v.length * 2);
for (int i = 0; i < v.length; i++) {
int b = v[i] & 0xFF;
sb.append(HEX_DIGITS.charAt(b >>> 4)).append(HEX_DIGITS.charAt(b & 0xF));
}
return sb.toString();
}

PHP's sha1() encodes each byte of the output as hexadecimal by default, but you can get the raw output by passing true as the second argument:
$digest = sha1($password, true); // This returns the same string of bytes as md.digest()
Then pass the digest to base64_encode and you are done:
base64_encode(sha1($password, true));
This returns the exact same SHA-1 hash as your java code.